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Direct estimation of blind zero-forcing equalizers based on second-order statistics

2000; Institute of Electrical and Electronics Engineers; Volume: 48; Issue: 8 Linguagem: Inglês

10.1109/78.852002

1941-0476

Xiaohua Li, H. Fan,

Advanced Adaptive Filtering Techniques

Most existing zero-forcing equalization algorithms rely either on higher than second-order statistics or on partial or complete channel identification. We describe methods for computing fractionally spaced zero-forcing blind equalizers with arbitrary delay directly from second-order statistics of the observations without channel identification. We first develop a batch-type algorithm; then, adaptive algorithms are obtained by linear prediction and gradient descent optimization. Our adaptive algorithms do not require channel order estimation, nor rank estimation. Compared with other second-order statistics-based approaches, ours do not require channel identification at all. On the other hand, compared with the CMA-type algorithms, ours use only second-order statistics; thus, no local convergence problem exists, and faster convergence can be achieved. Simulations show that our algorithms outperform most typical existing algorithms.